Microsoft 365 Apps Enterprise in the classic Outlook desktop client does not include a native strike-through text button in the formatting ribbon. This absence is by design, as standard email clients prioritize bold and italic styles for emphasis rather than deletion indicators. To achieve this effect, you must use alternative methods such as HTML editing or third-party add-ins.
Understanding the Interface Limitations
The confusion often arises because users expect every common text formatting option to have a dedicated icon in the Home tab. In the classic Outlook interface, which runs on Microsoft 365 Apps Enterprise, the font formatting toolbar is streamlined. It includes options like Bold (B), Italic (I), Underline (U), and Font Color, but deliberately omits Strikethrough. This is not a bug or a missing feature due to corruption; it is a standard configuration of the Word editor engine used within Outlook messages.
Unlike web-based versions of email clients that might offer more flexible rich-text editors, the classic Outlook client relies heavily on the Microsoft Word rendering engine. While Word itself has a strikethrough button in its ribbon, Outlook’s integration does not expose this specific command in the default message composition view. This limitation affects all users with Microsoft 365 enterprise subscriptions who are using the traditional desktop application.
Method 1: Using the Format Text Dialog Box
The most reliable built-in method to apply strikethrough formatting without installing additional software is through the Font dialog box. Although there is no quick-access button on the ribbon, the underlying functionality exists within the deeper settings of the text formatter.
- Select the Text: Highlight the word or sentence you wish to strike through in your new email body.
- Open Font Settings: Click the small diagonal arrow in the bottom-right corner of the Font group on the Home tab. Alternatively, you can press
Ctrl + Dto open the Font dialog directly. - Navigate to Effects: In the dialog box that appears, look for the section labeled Effects.
- Apply Strikethrough: Check the box next to Strikethrough. You can also choose Double Strikethrough if your compliance standards require it.
- Confirm: Click OK to close the dialog. The selected text will now display with a line through it.
This method works consistently across all versions of Microsoft 365 Apps Enterprise. It is important to note that this changes the formatting for the current selection only. If you need to apply this frequently, consider adding the Font dialog shortcut to your Quick Access Toolbar for faster access.
Method 2: Editing as HTML
For users who prefer a more visual approach or need to format large blocks of text quickly, switching to HTML source view can be effective. This method bypasses the ribbon limitations entirely by allowing direct code manipulation.
- Compose in HTML: Ensure your email is being composed in HTML format. Most enterprise accounts default to this, but you can verify it in the Format Text tab under Prioritize Plain Text (ensure it is unchecked).
- Switch to Source View: In the Format Text tab, click the HTML button. This opens a window showing the raw HTML code of your email.
- Insert Tags: Locate the text you want to modify in the code. Wrap the relevant words with the
<s>or<strike>tags. For example, changeHello Worldto<s>Hello</s> World. - Return to Normal View: Close the HTML source window. The email body will render the strikethrough effect correctly.
This technique is particularly useful when copying and pasting content from other sources where formatting might get lost. However, be cautious when editing HTML manually, as breaking the structure can cause layout issues in some email clients. If you are looking to enhance your email workflow further, you might find our guide on How to Add an Internal Link in Outlook Email Using 'file:///' helpful for managing complex document references.
Method 3: Third-Party Add-ins
If the built-in methods feel too cumbersome for daily use, the Outlook Store offers various add-ins that restore missing formatting buttons. These extensions integrate directly into the ribbon, providing a one-click solution for strikethrough.
To install an add-in, go to the Insert tab and select Get Add-ins. Search for "strikethrough" or "formatting tools." Review the permissions required by each add-in before installation, as enterprise security policies may restrict certain third-party scripts. Once installed, the add-in will typically appear in your ribbon or sidebar, offering immediate access to the feature. This approach is ideal for teams that require strict version control or audit trails where strikethrough is a standard notation for corrections.
Considerations for New Outlook
It is crucial to distinguish between the classic Outlook client and the "New Outlook" for Windows. The New Outlook uses a different architecture based on the Chromium browser engine, similar to Edge or Chrome. Some users mistakenly believe that because it is newer, it should have more features. However, the New Outlook currently has limited rich-text editing capabilities compared to the classic version. If you are migrating to the New Outlook, check Missing junk email privacy option in new Outlook business account (Microsoft 365 E3 account) for other known UI differences that may affect your workflow. The classic client remains the most robust option for detailed email formatting needs.
Frequently Asked Questions
Why is the strikethrough button missing in my Outlook ribbon?
Outlook uses the Microsoft Word editor for composing emails, but Microsoft chose not to place the strikethrough button on the default Home ribbon to keep the interface clean. The functionality still exists within the Font dialog box, even though it lacks a quick-access icon.
Does Ctrl+D apply strikethrough in Outlook?
No, Ctrl+D opens the Font dialog box in Outlook, just as it does in Word. It does not directly apply strikethrough formatting. You must manually select the strikethrough option inside the dialog after pressing the shortcut.
Will strikethrough text display correctly on mobile devices?
Most modern mobile email clients support the HTML <s> or <strike> tags, so the formatting should appear correctly. However, some older or simpler email apps may ignore these tags, displaying the text normally instead.
Can I add strikethrough to the Quick Access Toolbar?
You cannot add the strikethrough button directly to the Quick Access Toolbar because it does not exist as a standalone ribbon command in Outlook. You can, however, add the Font dialog launcher to your toolbar for faster access to the setting.
Is there a keyboard shortcut specifically for strikethrough?
There is no default single-keyboard shortcut for strikethrough in Outlook. You must use the mouse to navigate to the Font dialog or use an add-in that provides a custom shortcut. Word allows Ctrl+Shift+X, but this does not work in Outlook.